JP2008196481A - Micro-pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To transport fluid in a microchip or biochip flow path without depending on the inertial force or lifting force of a driving element or a capacity change of the flow path. <P>SOLUTION: This micro-pump comprises the U-shaped flow path 20 formed by a flow path wall 4 of a microchip or a biochip. The U-shaped flow path has a flow-in side flow path portion 21 and a flow-out side flow path portion 22. Disc-like, columnar or cylindrical rotors 10, 90 are rotatably arranged in a turn-around portion 23 between the flow paths 21, 22. The rotors are opposed to the front end face of a partition wall 5 partitioning the flow paths 21, 22. The rotors are rotationally driven by remote driving means (laser beams L, L1, L2, L3) in the state that their rotation center axes (X-X) are positioned. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a micropump, and more particularly to a micropump that can be disposed in a microchip having a channel cross-sectional dimension of 1 mm or less or a channel in a biochip.

  There is known an optical modeling method in which a photopolymerizable resin material is irradiated with laser light to model a three-dimensional photopolymer. The photopolymerizable resin is also called a photocurable resin. For example, Japanese Patent Application Laid-Open No. 2001-158050 and Japanese Patent Application Laid-Open No. 11-170377 disclose a method for manufacturing a microstructure using a photo-polymerizing resin stereolithography method. In the optical modeling method, a liquid photopolymerizable resin material is irradiated with laser light, and a three-dimensional structure made of the photopolymer is modeled in the liquid resin material. According to such an optical shaping method, by accurately controlling the condensing point of laser light and two-photon absorption, a micro-structure such as a micro gear having a relatively complicated three-dimensional structure can be used as a photopolymerizable resin raw material. Can be molded with high accuracy.

  As a method of driving the microstructure formed by photo-polymerization resin stereolithography, the movable part of the microstructure is irradiated with laser light, and the condensing point of the laser beam is moved while the movable part is optically trapped. A method for driving a microstructure that drives a movable part is known (Japanese Patent Laid-Open No. 2003-25295).

  Japanese Laid-Open Patent Publication No. 2001-252897 discloses a microchip including an optical pressure mixer that mixes and stirs a sample solution and a reagent solution using the principle of light driving. The optical pressure mixer is formed by a lithography technique, and is arranged at the junction of the sample liquid flow path and the reagent liquid flow path. The light pressure mixer is irradiated with the laser light, and the light pressure mixer is rotated by the light pressure, and the sample solution and the reagent solution are mixed and stirred at the junction.

  As a fluid transport method using the principle of light driving, a method has been proposed in which fine particles suspended in a liquid are remotely operated with a laser beam and the liquid in the microchip is caused to flow using the movement of the fine particles.

  In recent years, research and development of a microchemical analysis system that performs a chemical synthesis analysis process using a microchip or a biochip has attracted attention. In general, in this type of microchip or the like, a fluid containing DNA or protein is transported by electrophoresis, or a relatively large external device 101 such as an external syringe pump is connected to a fluid line as shown in FIG. A system configured to be connected to the outlet of the microchip 100 by 102 is used. In the system using the external device 101, the discharge port of the external device 101 is connected to the analyzer 105 by the fluid conduit 103, and the fluid in the fluid supply system 106 is controlled by the microchip 100 and the external device 101. 105 is fed.

A disc-type pump structure applicable from a normal scale (dimensions on the order of millimeters, inches or feet) to a microscale (dimensions on the order of micrometers) is described in International Publication No. WO2005 / 024230. The pump described in this publication is mainly composed of a rotating disk disposed in a pump housing, a wiper partially traversing the surface of the rotating disk, and a motor connected to the rotating disk. When the disk rotates, a rotational momentum due to viscous force is imparted to the fluid, and centrifugal force acts on the fluid, and the fluid is directed from the surface of the disk to the downstream flow path by the action of the wiper.
JP 2001-158050 A JP-A-11-170377 JP 2003-25295 A JP 2001-252897 A PCT International Publication WO2005 / 024230

  In the above-described microchemical analysis system using the external device 101, problems such as liquid leakage or air bubbles are likely to occur at the connection portion of the fluid conduit 102, which causes a decrease in analysis accuracy. In addition, the internal volume of the external device 101 and the external conduits 102 and 103 is considerably larger than the volume of the internal flow path of the microchip 100. Therefore, the fluid circuit including the external device 101 and the fluid conduits 102 and 103 is A relatively large amount of samples and reagents must be retained as a whole. As a result, there is a limit to the amount of samples and reagents, and the problem that it is difficult to reduce the cost required for the analysis process as desired.

  On the other hand, the optically drivable optical pressure mixer described in Patent Document 4 has a rotor that can be disposed in the flow path of the microchip. The rotor is arranged at a junction where three or more straight flow paths merge. When the rotor of the optical pressure mixer rotates, fluid pressure is generated in the vicinity of the rotor, and mixing and agitation of different fluids is performed at the junction. The fluid pressure formed in the vicinity of the rotor may work effectively in mixing and stirring the fluid. However, since the pressures in the high pressure region and the low pressure region around the rotating body act so as to cancel each other, a pressure gradient or fluid transport force in the flow path direction that effectively works for fluid transport cannot be obtained. Therefore, continuous transportation of fluid cannot be performed by the optical pressure mixer of this structure.

  Further, in the above-described fluid transport method in which fine particles that can be remotely controlled by laser light are suspended in a liquid and the fluid in the chip is caused to flow by the movement of the fine particles, the fine particles are suspended at an indeterminate position when the laser light is interrupted. For this reason, it is extremely difficult to put into practical use a method for controlling the fluid in the chip using such fine particles.

  On the other hand, by applying the pump structure described in PCT International Publication No. WO2005 / 024230 to a micropump, a micropump that can be incorporated into a microchip of a microchemical analysis system may be realized. However, the pump structure described in this International Publication has a configuration in which one side surface of the flow path is formed by the disk surface of the rotating disk, and the fluid transport function of the pump is a relatively wide range of disk surfaces and fluids. Depending on the viscous frictional force between them, the centrifugal force acting on the fluid on the disk surface, and the turning action of the wiper partially crossing the disk surface. In the case of a micropump with this configuration, the diameter of the disk surface must be set relatively large in order to ensure sufficient viscous frictional force and centrifugal force, and considering the distance between the disk surface and the fluid The flow path must be significantly flattened to the disk surface side. For this reason, when the pump structure described in the above-mentioned International Publication is applied to a micropump such as a microchip, it is necessary to increase the flow path width, which causes design difficulties due to dimensional reasons and the like.

  On the other hand, the present inventor has proposed a micropump configured to optically drive a pair of rotors supported on a pair of fixed shafts in PCT international application PCT / JP2006 / 314707. The micropump with this configuration achieved the intended purpose from the viewpoint of effectively transporting fluid in the flow path in the microchip or biochip.

  However, this type of micropump mainly utilizes the inertial force or lift force applied to the fluid by the drive element, or the volume change of the flow path caused by the drive of the drive element. For this reason, there is a concern that biological samples such as cells or bacteria contained in the fluid are destroyed or damaged by the physical action of the driving element.

  The present invention has been made in view of such problems, and the object of the present invention is not to depend on the inertial force or lift force of the drive element or the volume change of the flow path, but within the microchip or biochip. An object of the present invention is to provide a micro pump capable of transporting a fluid in a flow path.

In order to achieve the above object, the present invention is a micropump that can be disposed in a flow path in a microchip or a biochip,
A U-shaped channel having an inflow side channel part and an outflow side channel part partitioned by a partition;
A disk shape, a columnar shape, or the like, which is rotatably arranged at the folded portion of the U-shaped flow path so as to face the front end surface of the partition wall, and whose rotation center axis is positioned and rotated by a remote driving means. A micropump characterized by having a cylindrical rotor.

  The micropump of the present invention has a structure in which a disk-shaped, columnar, or cylindrical rotor is disposed at a folded portion of a U-shaped flow path. The rotor is remotely driven by remote drive means. The fluid in the flow path makes frictional contact with the outer peripheral surface of the rotor, and the rotor drags or drags the fluid around the rotor in the circumferential direction. The fluid is continuously transported from the inflow side flow path portion toward the outflow side flow path portion by the drag action or drag action of the rotor. The micropump with such a configuration precisely arranges a plurality of rotors like a lobe pump or transports fluid without driving the rotor in meshing like a gear pump. In addition, the micropump of the present invention has a structure that mainly depends on the viscous force of the fluid without depending on the volume change of the flow path. For this reason, fluid pulsation hardly occurs in the flow path, and biological samples such as cells and bacteria are transported without being destroyed or damaged.

  A pressure gradient that rises toward the outflow side flow path portion is formed in the fluid at the folded portion. This pressure gradient acts to prevent fluid transport. However, according to the analysis and experiment of the present inventor, the fluid biased by the frictional contact with the outer peripheral surface of the rotor does not flow from the inflow side flow path portion to the outflow side flow path portion in spite of such a pressure gradient. It turned out to flow toward. This is thought to be due to the characteristics of the fluid in the microscale channel where the viscous force is dominant over the inertial force.

  The inflow side flow path portion and the outflow side flow path portion of the U-shaped flow path are preferably arranged in parallel, but at an angle that converges or expands toward the folded portion, the inflow side flow path portion and the outflow side flow portion A channel portion may be disposed.

  According to the micropump of the present invention, the fluid in the microchip or biochip channel can be transported without depending on the inertial force or lift of the drive element and the change in volume of the channel.

  According to a preferred embodiment of the present invention, the rotor is made of a cured material of a photopolymerizable resin having optical transparency, and laser light is used as remote drive means. The rotor is captured by the light trapping action of the laser light. It is also possible in principle to use an external field such as a magnetic field or an electric field as another remote driving means. The rotor is formed of a material that is driven in response to such changes in the external field.

  When laser light is used as the remote drive means, the rotor is remotely driven by the optical drive action of the laser light and rotates about its rotation center axis. Preferably, the rotor is disposed at the center of the rotor and is irradiated with the first laser beam, and a pair is disposed at both sides of the center axis and irradiated with the second and third laser beams, respectively. And a driven shaft. More preferably, the rotor has a circular bottom plate, an outer peripheral wall connected to an outer edge portion of the bottom plate, and a hollow region formed inside the outer peripheral wall, and the central shaft and the driven shaft are erected on the bottom plate. Is done.

  It is also possible to rotate the rotor by the radiation pressure generated by condensing the laser beam without scanning the laser beam. Such a rotor preferably has a trap portion that is optically trapped and a plurality of blades or blades extending radially outward from the rotation center axis, and the trap portion and the radially inner end of the blade or blade. Are integrally connected in the axial direction of the rotation center axis. More preferably, the wings or blades are arranged point-symmetrically on both sides of the trap part and are integrally connected to the trap part in series. A wing | blade or a blade | wing has a shape which the rotational force of a predetermined direction produces with the radiation pressure of a laser beam. The rotor has a cylindrical body substantially concentric with the rotation center axis, and the wings or blades are accommodated in the cylindrical body and integrated with the cylindrical body.

  According to a further preferred embodiment of the present invention, the inflow side flow path part and the outflow side flow path part are arranged in parallel, and the center of the rotor is positioned on the center line of the partition wall. The flow path and the rotor have a symmetrical shape with respect to the center line of the partition wall. Preferably, the front end surface of the partition wall has a curved surface complementary to the outer peripheral surface of the rotor, and the distance (gap size) between the front end surface of the partition wall and the outer peripheral surface of the rotor is the rotor diameter × 0. The dimension value is set to 3 or less. More preferably, the rotor floats in the liquid in the U-shaped flow path, is captured by the remote drive means, and its rotation center axis is positioned.

  Preferably, the U-shaped channel includes a connection channel part that connects the inflow side channel part and the outflow side channel part. The connection channel portion includes a curved channel having an effective channel width. The curved flow path is defined by a curved surface continuous with the outer flow path wall surfaces of the inflow side flow path portion and the outflow side flow path portion, and the outer peripheral surface of the rotor. It is desirable to set the flow path widths of the inflow side flow path part and the outflow side flow path part to a dimension value smaller than the diameter of the rotor and to a dimension value of rotor diameter × 0.7 or more. By optimizing the clearance between the partition tip and flow path walls and the outer peripheral surface of the rotor, the pressure gradient around the rotor and the fluid transport force due to the viscous force of the fluid are properly balanced. , Fluid can be transported in a steady and unidirectional manner.

  If desired, a plurality of folded portions may be arranged in series or tandem, and a rotor may be placed in each folded portion.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a perspective view for explaining the principle of forming a microstructure on a glass substrate by a two-photon absorption type stereolithography.

  In FIG. 1, the condensing spot S of the laser beam L is formed inside the photopolymerizable resin raw material 1 on the glass substrate 2, and the liquid resin raw material (raw material 1) is tertiary by controlling the position of the condensing spot S. An optical modeling method for modeling an original microstructure polymer is shown.

  In the stereolithography shown in FIG. 1, a two-photon micro stereolithography apparatus (not shown) having a light source of near-infrared (or red) femtosecond pulsed laser light L is used. As shown in FIG. 1A, the near-infrared (or red) laser light L of the light source is irradiated to the photopolymerizable resin raw material 1 on the glass substrate 2 through a short focus lens (not shown). . The glass substrate 2 and the raw material 1 are transparent to the laser light L. The laser light L is condensed inside the raw material 1 to form a condensing spot S. A two-photon absorption phenomenon that induces the same effect as absorption of ultraviolet rays in near infrared rays is induced in the focused spot S, and only the raw material 1 in the vicinity of the focal position (the focal spot S) is polymerized. As shown in FIGS. 1B to 1D, the laser system scans the condensing spot S within the raw material 1 to form a photopolymer 3 having a desired contour. The raw material 1 and the glass substrate 2 are washed with a solvent such as ethanol after removing the unpolymerized raw material 1, and thus a photopolymer 3 having a desired contour is formed on the glass substrate 2. Processing resolution by such an optical shaping method is generally about 0.1 to 10 μm.

  FIG. 2 shows a U-shaped flow path (U-shaped channel) 20 and the rotor 10 formed on the glass substrate 2 by such an optical modeling method.

  On the board | substrate 2, the flow-path wall 4, the partition 5, and the rotor 10 are shape | molded by the optical modeling method of photopolymerizable resin. The flow path wall 4 forms a parallel outer flow path wall surface 6 and a curved surface 7 continuous to the outer flow path wall surfaces 6 on both sides, and the partition wall 5 forms a parallel inner flow path wall surface 8. The channel wall surfaces 6 and 8 and the curved surface 7 are arranged perpendicular to the substrate 2. A top wall surface 9 parallel to the substrate 2 is formed by the flow path wall 4. Thus, the U-shaped flow path 20 having the straight flow path portions 21 and 22 and the connection flow path portion 23 having a rectangular flow path cross section is formed on the substrate 2 by the flow path walls 4 and the partition walls 5. The rotor 10 and the U-shaped flow path 20 constitute a microdisk pump (micropump) of the present invention.

  The channel portions 21 and 22 have the same channel widths W1 and W2. The curved surface 7 is a semicircular curved surface having a curvature radius R <b> 1 with respect to the center of the rotor 10. A curved surface 24 that is complementary to the outer peripheral surface 11 of the rotor 10 is formed at the tip of the partition wall 5. The curved surface 24 is a curved surface having a width W3 and a curvature radius R2 with respect to the center of the rotor 10.

  FIG. 3 is a perspective view and a partially broken perspective view showing the structure of the rotor 10.

  The rotor 10 is a separate rotating element independent of the substrate 2, the flow path wall 4, and the partition wall 5. The rotor 10 includes a true circular outer peripheral wall 12 having a radius R3 having an outer peripheral surface 11, a true circular bottom plate 13 having a radius R3, and shafts 14, 15, and 16 disposed on the bottom plate 13. The outer edge of the bottom plate 13 is connected to the lower end of the outer peripheral wall 12. The outer peripheral wall 12 and the bottom plate 13 constitute a hollow disc having a hollow portion 17. The shaft portions 14, 15, and 16 are erected vertically on the upper surface of the bottom plate 13, and are aligned in the diameter direction of the rotor 10 at equal intervals. The shaft portion 15 is disposed at the center of the rotor 10, and the center axis of the shaft portion 15 constitutes the rotation center axis XX of the rotor 10.

  As shown in FIG. 2, the outer peripheral surface 11 is separated from the curved surface 7 by a distance G <b> 1, and a curved channel 25 having an effective channel width G <b> 1 is formed between the outer peripheral surface 11 and the curved surface 7. . The outer peripheral surface 11 is also spaced apart from the curved surface 24 by a distance G2, and a gap 26 is formed between the outer peripheral surface 11 and the curved surface 24.

  FIG. 4 is a perspective view showing the operating principle of the microdisk pump.

  As shown in FIG. 4, three independent laser beams L1, L2, and L3 are applied to the shaft portions 14, 15, and 16, respectively. The flow path wall 4, the partition wall 5, and the rotor 10 are permeable to the laser beams L1, L2, and L3. The laser beams L1, L2, and L3 are condensed inside the shaft portions 14, 15, and 16, and condensed spots T1, T2, and T3 are formed in the shaft portions 14, 15, and 16, respectively.

  Optical trapping is a technique for capturing an object at the focal point (condensed spots T1, T2, T3) of laser light (laser beams L1, L2, L3) using the radiation pressure of light. This utilizes the principle that when the light enters the object and refracts, a change in the momentum of the light occurs and the force acting on the object acts on the object as the radiation pressure of the light. The resultant force of the radiation pressure acts on the object in the direction toward the laser light collecting point, so that the object can be captured at the laser light L collecting point. The light trapped object is a transparent or translucent object (an object through which light passes) having a refractive index higher than that of the fluid, and is not directly related to the material of the object. For this reason, the thing of the material which forms the transparent or translucent rotor 10 after hardening is used as said photopolymerizable resin. In addition, since the principle of such optical trapping is already known, further detailed description regarding optical trapping is omitted.

  The shafts 14, 15, and 16 are captured (light trapped) by the laser beams L1, L2, and L3, respectively, and move or stop according to the movement, displacement, or scanning of the laser beams L1, L2, and L3.

  As shown in FIG. 4, the laser beam L2 constrains the center of the shaft portion 15 on the rotation center axis XX. The laser beams L1 and L3 rotate in the same direction (clockwise direction) around the rotation center axis XX, and the shaft portions 14 and 16 captured by the laser beams L1 and L3 are rotated about the rotation center axis XX. Move in the same direction (clockwise direction). As a result, the rotor 10 rotates in the direction of the arrow about the axis XX.

  The outer peripheral surface 11 of the rotor 10 is in frictional contact with the liquid in the U-shaped channel 20, and the liquid is dragged or dragged by the rotational movement of the outer peripheral surface 11. That is, the liquid receives the rotational force of the rotor 10 due to its viscosity, and flows from the connection flow path portion 23 to the straight flow path portion 22. This action is considered to be due to the characteristic of the microscale device in which the viscosity of the fluid greatly affects the motion of the fluid as compared with the inertial force of the fluid. Here, a relatively high fluid pressure is generated in the region (transition region 30 (FIG. 5)) where the connecting flow channel portion 23 transitions to the straight flow channel portion 22, but the rotor 10 and the U-shaped flow channel 20 The dimensions and positional relationship are set so that the fluid flow is not blocked by the fluid pressure.

Hereinafter, dimensions and positional relationships of the rotor 10 and the U-shaped flow path 20 will be described. The following explanation is based on the knowledge obtained by the present inventor from the coincidence or commonality between the result of the micro numerical fluid analysis using the finite element method (FEM) and the result of the demonstration experiment. In this analysis and experiment, glycol ether assert (density 960 kg / m ² , viscosity coefficient 1.92 × 10 ⁻³ Pa · S) was used as the transport liquid. The diameter (2 × R3) of the rotor 10 was set to 10 μm (a constant value).

  5 (A) and 5 (B) are plan views schematically showing the relationship between the channel widths W1 and W2 and the diameter (2 × R3) of the rotor 10, and FIG. It is a diagram which shows the relationship between flow-path width W1, W2 and the flow velocity (flow rate) of the fluid.

  FIG. 5A illustrates a state where the channel widths W1 and W2 are enlarged, and FIG. 5B illustrates a state where the channel widths W1 and W2 are reduced. The rotor 10 is rotationally driven by the laser beams L1, L2, and L3 at a rotational speed of 5.7 rpm, and the liquid in the U-shaped flow path 20 flows from the straight flow path portion 21 to the straight flow path portion 22. . When the channel widths W1 and W2 are changed in the range of 5 to 10.5 μm, the flow rate of the liquid flowing out from the connection channel part 23 to the straight channel part 22 changes as shown in FIG. The maximum flow rate was obtained at the path widths W1 and W2 = 8.5 μm.

  As shown in FIG. 5B, when the channel widths W1 and W2 are set to be less than 7 μm, a high fluid pressure is generated in the transition region 30. In the region 31 before and after the transition region 30, the fluid pressure gradually decreases. Accordingly, a pressure gradient showing a maximum value in the transition region 30 is formed in the U-shaped flow path 20, and as a result, the liquid (arrow 33) urged by the rotor 10 is prevented from flowing in the transition region 30. In the transition region 30, it flows backward (arrow 34) and flows along the outer flow path wall surface 7 toward the flow path portion 21. For this reason, the flow rate of the microdisk pump decreases as shown in FIG.

  On the other hand, as shown in FIG. 5A, when the channel widths W1 and W2 are set to 7 μm or more, the pressure gradient of the liquid in the U-shaped channel 20 is leveled, and the linear channel portion 21 is changed to the linear channel portion. 22 smoothly flows. Accordingly, the dimension values of the channel widths W1 and W2 are preferably set to a value of 70% or more of the diameter (2 × R3) of the rotor 10.

  Further, when the flow path widths W1 and W2 are set to dimension values larger than the diameter (2 × R3) of the rotor 10, the rotor 10 flows out from the connection flow path portion 23 to the straight flow path portions 21 and 22. Is concerned. For this reason, the dimension values of the channel widths W1 and W2 are preferably set to values smaller than the diameter (2 × R3) of the rotor 10.

  FIG. 6 shows a change in fluid pressure in the vicinity of the outer peripheral surface 11.

  As described above, a high fluid pressure is generated in the transition region 30 when the rotor 10 rotates. As shown in FIG. 6B, the fluid pressure drops toward the upstream flow path portion 21 and rises toward the downstream flow path portion 22 with respect to the neutral point on the center line of the partition wall 5. . The maximum pressure appears in the transition region 30 adjacent to the gap 26 and the minimum pressure appears in the transition region 35 of the flow path portions 21, 23 adjacent to the gap 26. The fluid pressure in the transition region 30 gradually decreases toward the downstream channel portion 22, and the fluid pressure in the transition region 35 gradually increases toward the upstream channel portion 21. When the fluid pressure in the transition region 30 exceeds approximately 10 mPa, a back flow 34 is generated as shown in FIG. 5B, so it is desirable to set the fluid pressure in the transition region 30 to 10 mPa or less.

  FIG. 7 shows the relationship between the rotational speed of the rotor 10 and the flow rate (average flow rate) of the microdisk pump.

  The correlation between the rotational speed and the flow velocity (liquid flow velocity) shown in FIG. 7 is a theoretical correlation based on the result of the micro numerical fluid analysis using the finite element method (FEM) and the experimental result of the demonstration experiment. Approximate both analysis results and experimental results. As shown in FIG. 7, the flow rate of the microdisk pump is approximately directly proportional to the rotational speed of the rotor 10, and increases as the rotational speed increases. According to the inventors' experiment, the microdisk pump achieved a flow rate of about 3 pl / min.

  FIG. 8 shows the relationship between the dimension value of the distance G2 (gap) and the flow velocity (flow rate) of the microdisk pump.

  The center position of the rotor 10 is determined by capturing the shaft portion 15 by the laser beam L2. When the rotor 10 is displaced by the laser beam L2 to move away from or approach the curved surface 24 of the partition wall 5, the distance G2 of the gap 26 changes. FIG. 8C is a diagram showing changes in the flow rate of the microdisk pump associated with changes in the distance G2.

  As shown in FIG. 8A, when the gap 26 is reduced, the flow rate of the microdisk pump increases, and when the gap 26 is enlarged as shown in FIG. 8B, the flow rate of the microdisk pump decreases. FIG. 8C shows the correlation between the distance G2 and the flow velocity, and the liquid flow velocity is approximately inversely proportional to the dimension value of the distance G2. Therefore, the flow rate of the microdisk pump can be set or controlled by setting or controlling the distance G2 (gap 26).

  FIG. 9 shows the flow velocity distribution of the flow path 20 in relation to the height of the rotor 10 and the U-shaped flow path 20.

  The height dimension h of the rotor 10 is set to a value smaller than the height dimension H of the flow path 20. Therefore, gaps 27 and 28 are formed between the upper and lower surfaces of the rotor 10 and the substrate 2 and the top wall surface 9 as shown in FIG. FIG. 9 shows changes in the flow rate of the microdisk pump obtained when the total value E of the height dimensions E1 and E2 of the gaps 27 and 28 is set to 2 μm and 4 μm. In FIG. 9C, the horizontal axis (X axis) indicates the position in the channel in the height direction (distance (μm)) with respect to the neutral point J (height H / 2) in the height direction, The vertical axis (Y-axis) indicates the flow rate (μm / s) of the microdisk pump.

  When the gap dimension E (= E1 + E2) is decreased, the flow rate of the microdisk pump increases as shown in FIG. 9C. Even when the dimension E of the gaps 27 and 28 is increased, the problem of backflow due to pressure fluctuation (FIG. 5B) does not occur.

  FIG. 10A is a schematic plan view showing the relative angle θ of the straight flow path portions 21 and 22 in the folded portion (connection flow path portion 23) of the U-shaped flow path 20, and FIG. It is a diagram which shows the relationship between (theta), flow path width, and a linear part maximum flow velocity (maximum flow velocity of the linear flow path parts 21 and 22).

  When the relative angle θ of the straight flow path portions 21 and 22 is changed, the maximum flow velocity of the straight flow path portions 21 and 22 obtained when the rotor 10 is rotated decreases as the angle θ increases (FIG. 10B). ). The channel width can be preferably set to 11 mm or less, or to the diameter of the rotor 10 or less. It is desirable to set the angle θ to 90 degrees or less. According to the results of the analysis conducted by the present inventor regarding this example, when increasing the linear portion maximum flow velocity, it is desirable to set the angle θ = 0 degree as shown in FIG. In order to increase the flow velocity or flow rate, it is desirable to set the angle θ in the range of 30 to 90 degrees.

  FIG. 11 is a system configuration diagram schematically showing a configuration of a drive system for driving the microdisk pump.

  The drive system 50 has substantially the same configuration as that of the two-photon micro stereolithography apparatus used in the stereolithography shown in FIG. 1, and includes a light source 51, an ND filter 52, a shutter 53, a beam expander 54, and a galvanometer mirror 55. , An objective lens 56, a computer 57, a CCD camera 58, and a stage (not shown). The light source 51 is composed of a titanium sapphire laser device, and emits near-infrared laser light (wavelength: 750 nm). The laser light L passes through the ND filter 52 and the shutter 53, is expanded in beam width by the beam expander 54, and then converges in the rotor 10 by the galvano mirror 55 and the objective lens 56. The shutter 53 and the galvanometer mirror 55 are controlled by the computer 57 and can move the condensing position of the laser light L (condensing spots T1: T2: T3) to an arbitrary position. The drive system 50 has a configuration capable of individually controlling the laser beams L1, L2, and L3.

  As shown in FIG. 4, the drive system 50 irradiates the shaft portions 14, 15 and 16 with laser beams L 1, L 2 and L 3. The drive system 50 operates the shutter 53 and the galvanometer mirror 55 under the control of the control program stored in the storage unit of the computer 57, optically traps the shafts 14, 15, and 16 with the laser beams L1, L2, and L3, The rotor 10 is captured. The drive system 50 controls the shutter 53 and the galvanometer mirror 55 to move the shaft portions 14 and 16 in the same rotational direction by the laser beams L1 and L3. The rotor 10 rotates around the shaft portion 15 whose position is restricted by the laser beam L2. Preferably, the laser beams L1 and L3 are irradiated so as to form the condensed spots T1 and T3 near the front surface or edge of the shaft portions 14 and 16 in the rotation direction, and the shaft portions 14 and 16 are irradiated with the laser beams L1. , Pulled by L3.

  12 and 13 show another embodiment of the microdisk pump. The micro disk pump has a helical rotor (helical rotating element) manufactured by a photo-molding method of a photopolymerizable resin having light permeability.

  The microdisk pump provided with the rotor 10 shown in FIGS. 2 to 4 is configured to drive the rotor 10 by scanning the laser beam with a galvano mirror, and thus requires a laser scanning system. This makes it difficult to reduce the size of the device. On the other hand, it is possible to autonomously rotate the rotor with the radiation pressure generated by condensing the laser light without scanning the laser light and utilizing the change in the angular momentum of the light.

  FIG. 12 is a perspective view illustrating the structure of the helical rotor 40 that rotates by condensing laser light.

  As shown in FIGS. 12A and 12B, the helical rotor 40 includes a shaft portion 42 having a trap portion 41 to be optically trapped on the proximal end side, and a plurality of (this book) connected to the tip of the shaft portion 42. In the example, it is composed of five spiral wings 43. The spiral blades 43 are arranged at equal intervals (angular intervals) from each other, and extend radially outward from the rotation center axis XX. The radially inner end of the spiral blade 43 is integrally connected to the tip of the shaft portion 42. Each spiral blade 43 has a blade shape that is entirely curved in a plan view. The plurality of spiral blades 43 as a whole have an appropriate shape anisotropy as shown in FIG. 12C, and a rotational force in a fixed direction is generated by a helical rotor by the radiation pressure of the laser light L (incident light, reflected light). Act on 40.

  The helical rotor 40 is designed to rotate in the clockwise direction when viewed in the direction of the laser beam L, and the rotational direction of the helical rotor 40 is determined by the relative positions of the trap portion 41 and the spiral blade 43. That is, when the spiral blade 43 is arranged on the light source side of the trap portion 41 as shown in FIG. 12A, the helical rotor 40 rotates in the clockwise direction when viewed from the light source side, but as shown in FIG. When the spiral blade 43 is disposed on the non-light source side of the trap portion 41, the helical rotor 40 rotates counterclockwise as viewed from the light source side.

  FIG. 13 shows a dual structure helical rotor 80 that is designed to rotate in a specific direction by utilizing such optical trapping characteristics.

  As shown in FIG. 13A, the helical rotor 80 has a shaft-shaped trap portion 81 that is optically trapped at the center. A plurality of spiral blades 83 and 84 arranged on both sides (upper and lower sides) of the trap part 81 are connected to the upper and lower surfaces of the trap part 81. The spiral blade 83, the trap part 81, and the spiral blade 84 are integrally connected in series.

  As shown in FIG. 13C, when the helical rotor 80 is irradiated with the laser light L and the condensed spot T is formed on the trap portion 81, the radiation pressure generated in the spiral blades 83 and 84 causes a certain direction (viewed from the light source side). In the clockwise direction). As a result, the helical rotor 80 rotates in a fixed direction around the axis XX. Thus, by unifying the rotation directions of the rotary blades 83 and 84 and increasing the rotational force, the helical rotor 80 can be rotated at the same time as the helical rotor 80 is captured by optical trapping.

  As shown in FIG. 13B, the helical rotor 80 is accommodated in the cylinder 85, and the radially outer ends of the spiral blades 83 and 84 are integrated with the cylinder 85. Thus, a cylindrical or cylindrical rotor 90 having a helical rotor 80 and having a cylindrical outer peripheral surface is formed, and the rotor 90 is irradiated in a certain direction by irradiation with laser light L as shown in FIG. Rotate to. The cylinder 85 functions to suppress fluid turbulence and to transmit a shearing force smoothly and continuously to the liquid to form a continuous laminar flow without pulsation. Since most of the radiation pressure generated in the cylinder 85 acts in the optical axis direction, it is considered that the effect of suppressing the rotational force is small. In addition, such a rotor 90 is integrally formed by the optical modeling method of a photopolymerizable resin having light transmittance, or the helical rotor 80 and the cylinder 85 formed by the optical modeling method of the photopolymerizable resin are integrally formed. It is manufactured by assembling.

The rotor 90 is disposed in the folded portion (connection flow path portion 23) of the U-shaped flow path 20 (FIG. 2) similarly to the rotor 10 described above, and constitutes the microdisk pump of the present invention. According to such a microdisk pump, the following advantages can be obtained.
(1) The rotor 90 can be rotated at high speed only by laser irradiation without requiring laser scanning.
(2) A light source integrated pump using an on-chip laser light source can be realized.
(3) Since it has a cylindrical shape as a whole, the viscous force can be efficiently transmitted to the fluid.
(4) The liquid pulsation during liquid transportation can be reliably prevented, and the soft biological sample such as cells can be reliably transported without being damaged.

  FIG. 14 is a plan view and a cross-sectional view taken along line III-III showing the configuration of a microchip incorporating the microdisk pump of the present invention.

  FIG. 14 shows a microchip 60 including a plurality of microdisk pumps P having different sizes. The microchip 60 has a fine flat plate structure in which the flow path wall 4 is coated on the glass substrate 2. The channel wall 4 forms a channel 62 having a predetermined form at a predetermined position. The micro separator 66, the micro tweezers 67, and the micro valve 68 are disposed at predetermined positions in the flow path 62. These fluid control devices are also formed in the flow path 62 by the optical modeling method together with the microdisk pump P.

  The microdisk pump P is inserted at a predetermined position in the flow path 62. The flow path portions 21 and 22 of the microdisk pump P open at predetermined positions of the flow path 62, and transport the liquid in the flow path 62 by the rotation of the rotor 10. The flow path 23, the micro separator 66, the micro tweezers 67, the micro valve 68, and the micro disk pump P constitute a fluid circuit that controls the liquid to be supplied to the analyzer 75.

  In the microchip 60 configured as described above, by rotating the rotor 10 of the microdisk pump P by optical trapping, a continuous flow from the fluid conduit 70 toward the fluid conduits 71, 72, 73, 74 is generated. It is formed in the flow path 62. The microchip 60 feeds the fluid in the fluid conduit 70 to the analyzer 75 without depending on external equipment such as an external syringe pump. Therefore, according to such a microchip 60, the connection process between the external device (external syringe pump and the like) and the microchip 60 is omitted, and problems such as liquid leakage and bubble mixing due to the external device connection are avoided. It becomes possible.

  Further, in such a chemical synthesis analysis process using the microchip 60, the amount of the sample or reagent or the like is reduced to reduce the cost required for the analysis process, and the labor for connecting external equipment is eliminated, thereby improving the work efficiency. be able to.

  Furthermore, since the microchip 60 having the above configuration can remotely drive each fluid control device with laser light, it requires the use of expensive and precise equipment such as a piezo device and an electrostatic actuator, and wiring associated therewith. do not do. Therefore, such a configuration of the microchip 60 is practically advantageous.

  FIG. 15 is a schematic plan view showing a modification of the microdisk pump P.

  A plurality of rotors 10 and U-shaped channels 20 can be arranged in tandem or in series according to the present invention. The flow rate (flow velocity) of the microdisk pump P is increased by the tandem arrangement or series arrangement of the rotor 10 and the U-shaped flow path 20.

  The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the above-described embodiments, and various modifications or changes can be made within the scope of the present invention described in the claims. Is possible.

  For example, in the above embodiment, all the components such as the fluid control device on the microchip, the flow path, and the pump housing are molded by the photo-molding method of the photopolymerizable resin, but the resin molded body molded by the injection molding method The flow path (including the U-shaped flow path) may be formed of other materials, such as the flow path of FIG. In this case, the photopolymerizable resin material is injected into the flow path, and the rotor is optically shaped in the flow path.

  Moreover, in the said Example, although the partition is equipped with a curved surface in the front-end | tip part, it is also possible to shape | mold the front end surface of a partition into a plane or a flat surface.

  Furthermore, in the above embodiment, the rotor floating in the liquid is disposed in the U-shaped flow path, but the rotor may be supported by a center fixed shaft that passes through the center of the rotor.

  The micropump of the present invention is disposed in a flow path of a microchip or a biochip, and is used for transporting or pumping fluid in the chip under control. The micropump energizes the fluid to form a continuous flow of fluid toward the subsequent analytical instrument or the like. The micropump can be suitably used as a biological sample transporting means for transporting not only a fluid but also a biological sample such as a cell without being destroyed or damaged. By using such a microchip equipped with a micropump, the troublesome and inefficient connection between the external device and the microchip or biochip is omitted, and problems such as liquid leakage and air bubbles are eliminated. In addition, it is possible to reduce the amount of sample and the like and to reduce the cost of the analysis process. In the future, it is expected that a disposable high-performance cell analysis system and the like will be realized according to the present invention.

  According to the present invention, the microchip is arranged on a microscope equipped with a drive system, and the micropump in the microchip is optically driven by the laser light of the drive system, thereby transporting fluid and controlling the fluid circuit. It becomes possible. This enables, for example, a microchemical analysis method in which automatic analysis is performed while observing an image of an observation microscope.

  Furthermore, the present invention relates to an integrated analysis chip in which a chip type laser such as a semiconductor laser is incorporated in a microfluidic circuit, and suggests its feasibility. Therefore, the present invention will significantly improve the use environment and applicability of microchips or biochips.

It is a perspective view for demonstrating the principle which shape | molds a microstructure on a glass substrate by the two-photon absorption-type stereolithography. It is the top view which shows the structure of the U-shaped flow path and rotor which were shape | molded on the glass substrate by the optical shaping method, II sectional view taken on the line, and II-II sectional view. It is the perspective view and partial fracture perspective view which show the structure of a rotor. It is a perspective view which shows the working principle of a micropump. 5 (A) and 5 (B) are plan views schematically showing the relationship between the channel width and the rotor diameter, and FIG. 5 (C) shows the relationship between the channel width and the flow velocity. FIG. 6A is a perspective view schematically showing the positional relationship between the rotor and the flow path, and FIG. 6B is a diagram showing a change in fluid pressure in the vicinity of the outer peripheral surface of the rotor. It is a diagram which shows the relationship between the rotational speed of a rotor, and the flow velocity of a micropump. 8A and 8B are plan views schematically showing the positional relationship between the partition wall and the rotor, and FIG. 8C is a view between the partition tip surface and the rotor outer peripheral surface. It is a diagram which shows the relationship between a gap | interval dimension and the flow velocity of a micropump. 9A is a cross-sectional view showing the height relationship between the rotor and the U-shaped channel, and FIGS. 9B and 9C are cross-sectional views and lines showing the flow velocity distribution in the height direction. FIG. 10A is a schematic plan view showing the relative angle θ of the straight flow path portion, and FIG. 10B is a diagram showing the relationship between the angle θ, the flow path width, and the straight portion maximum flow velocity. It is a system configuration figure showing roughly the composition of the drive system for driving a micro pump. 12 (A) and 12 (B) are perspective views showing a helical rotor (helical rotating element) designed to rotate autonomously with the radiation pressure generated by condensing laser light. 12 (C) is a cross-sectional view of the helical rotor. It is a perspective view which shows the structure of the rotor of the composite structure shape-designed so that it may rotate in a specific direction using the property of the helical rotor shown in FIG. It is the top view which shows the structure of the microchip incorporating the micropump, and the III-III sectional view taken on the line. It is a schematic plan view which shows the modification of a micropump. It is a perspective view which shows roughly the whole structure of the microchemical analysis system provided with the conventional microchip.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photopolymerizable resin raw material 2 Glass substrate 3 Photopolymer 4 Channel wall 5 Partition wall 6 Outer channel wall surface 7 Curved surface 8 Inner channel wall surface 9 Top wall surface 10 Rotor 11 Outer surface 12 Outer wall 13 Bottom plates 14 and 16 Axes (Driven shaft)
15 Shaft (center axis)
20 U-shaped channel 21 Straight channel part (inflow side)
22 Straight flow path (outflow side)
23 Connection flow path portion 24 Curved surface (partition wall tip surface)
25 Curved channel 26 Gap 30 Transition region 40, 80 Helical rotor 43, 83, 84 Spiral blade 41, 81 Trap part 85 Cylinder 90 Rotor L: L1: L2: L3 Laser light (laser beam)
T: T1: T2: T3 Condensing spot W1: W2 Channel width G2 Distance (gap size)
R3 Rotor radius P Micro disk pump

Claims (16)

A micropump that can be placed in a flow path in a microchip or biochip,
A U-shaped channel having an inflow side channel part and an outflow side channel part partitioned by a partition;
A disk shape, a columnar shape, or the like, which is rotatably arranged at the folded portion of the U-shaped flow path so as to face the front end surface of the partition wall, and whose rotation center axis is positioned and rotated by a remote driving means. A micropump comprising a cylindrical rotor.   Laser light is used as the remote drive means, and the rotor is made of a cured material of a photopolymerizable resin having optical transparency, captured by the light trapping action of the laser light, and by the light drive action of the laser light. The micropump according to claim 1, wherein the micropump is remotely driven and rotates about the rotation center axis.   3. The micropump according to claim 1, wherein the rotor floats in a liquid in the U-shaped flow path, is captured by the remote driving unit, and is positioned at a rotation center axis.   The U-shaped flow path has a connection flow path portion that connects the inflow side flow path portion and the outflow side flow path portion, and the connection flow path portion includes the inflow side flow path portion and the outflow side flow path portion. The micropump according to any one of claims 1 to 3, further comprising a curved flow path defined by a curved surface continuous with an outer flow path wall surface and an outer peripheral surface of the rotor.   5. The micropump according to claim 1, wherein a front end surface of the partition wall is formed as a curved surface that is complementary to an outer peripheral surface of the rotor.   The rotor is disposed at the center of the rotor and is irradiated with the first laser beam, and a pair of rotors disposed on both sides of the center axis and irradiated with the second and third laser beams, respectively. The micropump according to claim 2, further comprising: a driven shaft.   The rotor has a circular bottom plate, an outer peripheral wall connected to an outer edge portion of the bottom plate, and a hollow region formed inside the outer peripheral wall, and the central shaft and the driven shaft are erected on the bottom plate. The micropump according to claim 6, wherein   The rotor includes a trap portion that is optically trapped and a plurality of blades or blades that extend radially outward from the rotation center axis, and the trap portion and the radially inner end portion of the blade or blade are The micropump according to claim 2, wherein the micropump is integrally connected in an axial direction of the rotation center axis.   9. The micropump according to claim 8, wherein the blades or blades are arranged point-symmetrically on both sides of the trap part and are integrally connected in series to the trap part.   The rotor includes a plurality of blades or blades extending radially outward from the rotation center axis, and the blades or blades have a shape in which a rotational force in a predetermined direction is generated by a radiation pressure of laser light. The micropump according to claim 2.   The said rotor has a cylindrical body substantially concentric with the said rotation center axis line, The said wing | blade or blade | wing is accommodated in the said cylindrical body, and is integrated with this cylindrical body, The thru | or 8 characterized by the above-mentioned. 11. The micropump according to any one of 10 above.   12. The flow path width of the inflow side flow path part and the outflow side flow path part is set to a dimensional value within a range of rotor diameter × 0.7 to 1.0. The micropump according to any one of the above.   The distance between the front end surface of the partition and the outer peripheral surface of the rotor is set to a rotor diameter x 0.3 or less dimension value. A micropump as described in 1.   14. The micropump according to claim 1, wherein the inflow side flow path portion and the outflow side flow path portion are arranged in parallel.   15. The center of the rotor is positioned on the center line of the partition wall, and the flow path and the rotor have a symmetrical shape with respect to the center line of the partition wall. The micropump according to item 1.   The micropump according to any one of claims 1 to 15, wherein a plurality of the folded portions are arranged in series, and the rotor is arranged in each folded portion.

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